Lecture 7

Normal Galaxies

1. Types of galaxies

a. Spiral

b. Spiral barred

c. Elliptical

d. Irregular

2. Distribution of the galaxies in the Universe

a. Galaxy clusters

b. Galaxy superclusters

c. Collisions among galaxies

3. Mass of a galaxy

a. Mass of a spiral galaxy

b. Mass of an elliptical galaxy

4. Hubble’s Law

a. Recessional velocity

b. Hubble constant

c. Expansion of the Universe